Apparatus for printing images on substrates, in particular, those which use a plate having depressions filled with ink whereupon the substrate to be printed on is contacted with the plate, are known in the art. Additionally, apparatus for printing images on substrates, in particular, those which use a pad which contacts a plate having depressions filled with ink whereupon the pad prints the image on the substrate, are known in the art. Such transfer printing and pad printing apparatus require a source of the ink which is applied to the plate to fill the depressions in the plate. The apparatus also requires a means for removing ink from the surface of the plate without removing the ink filling the depressions.
Ink cup or reservoir devices which provide both functions are known in the art. The ink cup contains the ink and is held in position over the plate. The ink cup has a generally open bottom which allows ink to contact the surface of the plate including any depressions thereon. The ink cup also has a bottom edge which, when the ink cup is moved along the surface of the plate, acts to remove ink from the surface of the plate while leaving the ink in the depressions in the plate.
The ink cup must be kept in close contact with the surface of the plate and the force around the bottom edge of the ink cup must be even or ink leakage and incomplete removal of ink from the surface of the plate can occur. Providing for contact of the ink cup edge with the surface of the plate by means such as springs (U.S. Pat. Nos. 5,577,442 and 5,476,040) and magnets (U.S. Pat. Nos. 5,392,706, 5,537,921 and 5,003,872) is known. However, even with the use of such means to provide close contact between the ink cup edge and the surface of the plate, leakage or incomplete removal of ink from the surface of the plate can occur.
Accordingly, it would be desirable to provide a transfer printing or pad printing apparatus and a method for transfer printing or pad printing using an ink reservoir device which is held in close contact with the surface of the plate to minimize the occurrence of leakage or incomplete removal of ink from the surface of the plate.